The development of three potentially useful iron chelating drugs is continuing in the laboratory. 2,3-Dihydroxybenzoic acid was the first compound which was found to be useful as an iron chelator in the iron overload rat model. A double-blindstudy in Beta-thalassemia major has bee completed. Following one year, efficacy in terms of retardation of iron accumulation could not be documented. However, since the drug is minimally toxic and does leadto iron excretion, evaluation of 2,3-DHB as adjunctive therapy in combination with parenteral desferrrioxamine appears warranted and these studies are being initiated. Rhodotorulic acid is an hydroxamic type chelator which, when infused at a dose of 25 mg/kg over a 2 hour period in 5 patients, led to an average increased iron excretion of 0.93 mg/kg/day which was about 10% greater than the effect obtained with a comparable dose of desferrioxamine. Permission has been recently obtained from the FDA to continue evaluation of rhodotorulic acid in intramuscular injection. This route appears particularly promising because of the decreased solubility of the drug which should lead to slow absorption and perhaps greater resultant efficiency in terms of iron chelation. Cholylhydroxamic acid is a compound which appears to mimic cholic acid in that it is taken up by the intestine and participates in the enterohepatic circulation as a bile acid analog unless it chelates an iron molecule, in which case it is excreted in the stool. At present toxicological evaluation of this compound is being undertaken in animals and pending the results of these studies, we hope to petition the FDA to initiate clinical trials within the coming year.